JPS5863068A - Coreless motor - Google Patents

Abstract

PURPOSE:To increase the effective area of an armature coil and to improve the efficiency of a motor by a method wherein field magnets are positioned at the inside of the armature coil. CONSTITUTION:Field magnets 3a, 3b and 4a, 4b are fixed to the surface and reverse of a yoke 8 consisting of an iron plate or the like and fixed to a bearing pillar 5 so that the magnets may be reverse polarity each other in the shaft direction of a rotor shaft 9. An air core disk-shaped armature coil 11 is provided with free rotation by reserving a gap to the magnetic pole faces of the field magnets so as to surround the field magnets 3a, 3b, 4a, 4b and a magnetic path is formed by a case 1 and a case cover 2 consisting of a magnetic pole material and provided at the outside of the coil. This configuration can enlarge the field magnets as far as the position facing to the central section of the coil. Therefore, the part around the center of the coil can utilize for the generation of torque.

Description

[Detailed description of the invention] The present invention relates to a coreless motor.

Various configurations of coreless motors using air-core coils are known, but in all of them, only a portion of the total area of the coil effectively generates torque, and in principle, high efficiency can be achieved. It was impossible. For this reason, a coreless motor constructed to effectively utilize almost the entire area of the coil for torque generation has been proposed in Japanese Patent Application No. 55-18818, and a sectional view of such a coreless motor is shown in FIG.

In Fig. 1, 1 is a case made of magnetic material, 2 is a lid case also made of magnetic material, and 3α and 3b are field magnets formed in a fan shape, magnetized in a direction perpendicular to the surface, and fixed to the inner surface of case 1. Magnets 4α and 4b are field magnets that are also formed in a sector shape, magnetized in a direction perpendicular to the surface, and fixed to the inner surface of the lid case 2, and 5 is a cylindrical non-magnetic material fixed to the center of the lid case 2. 6 and 7 are bearings fixed to both openings of the bearing support 5; 8 is made of a magnetic material and is formed into a disk shape with a center hole; the center hole is located at the tip of the bearing support 5; A yoke is defined on the bearing strut 5 by fitting into it.

On the other hand, 9 is a rotor shaft rotatably supported by bearings 6 and 7, and lO is an air-centered disk-shaped thin plate of synthetic resin arranged along the outer surface of the yoke 8 with a predetermined gap from the outer surface. The coil frame 11 is an armature coil formed by winding a coil wire entirely in the radial direction around the coil frame 10 passing approximately through the center. A center hole l is formed in the center of one plane of the coil frame 10 so as not to touch the bearing support column 5.
Oα is formed 0b, and the center portion of the other plane serves as a support portion and is fixed to the rotor shaft 9. Therefore, the plane part of the coil 11 is held in a plane perpendicular to the rotor axis 9, and between the field magnet 3G+ 3b and the yoke 8 and the field magnet 4α
, 4b, respectively. In addition, 12 is a commutator fixed to the rotor shaft 9, 13α is a commutator 12 [a positive electrode brush in sliding contact, 1
Reference numeral 36 denotes a negative brush. By forming the armature coil in the shape of an air-core disk and rotatably disposing the armature coil so that its plane part is located in the field space, the brush 36 has a negative electrode. Lua'c has only the side surfaces as an ineffective part, and both flat parts as effective parts that generate torque over almost the entire area.
This improves the efficiency of the motor.

However, in such a configuration, since the center part of the armature coil is much thicker than the flat part, the coil 11
Field magnet 3α located outside of.

3b, 4α, and 46 cannot be enlarged to positions facing the center of the coil, so the coil portion near the center cannot be effectively used for torque generation, and the field magnet is located outside the coil, so magnetic leakage is likely to occur, and there is a limit to the improvement of motor efficiency. Also, the motor has an outer diameter of 4
If it is less than 08, the properties will deteriorate and it will be difficult to mold it.

An object of the present invention is to provide a coreless motor that can significantly improve efficiency and downsize by increasing the effective area of the armature coil.

The coreless motor according to the present invention is provided with an armature coil in the form of an air-centered disk, which is wound in the radial direction passing through the vicinity of the rotational axis of the motor, and is rotatably provided with an armature coil having opposite polarity in the direction of the rotational axis of the coil. By providing at least two pairs of field magnets, the area near the center of the coil is also effectively utilized for torque generation.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a cross-sectional view showing one embodiment of the present invention, in which parts equivalent to those in FIG. 1 are designated by the same reference numerals. In the present invention, the field magnetene) 3 (1, 3b and 4α,
4b is fixed to the bearing support 5, and the yoke 8 is made of an iron plate or the like.
The field magnets 3 are fixed to the front and back sides of the rotor shaft 9 so that their polarities are opposite to each other in the axial direction of the rotor shaft 9 as shown in the figure.
α, 3b, 4α, 4bf Surrounding the magnetic pole face of the field magnet and the air-core disc-shaped armature coil lli
The coil is rotatably provided, and a magnetic path is formed by a case l made of a magnetic material and a case lid 2 provided outside the coil, and the other structure is the same as that in FIG. 1.

In this way, by locating the field magnets 3α, 3b, 4a, and 4b inside the armature coil 11, it is possible to extend the field magnets 3α, 3b, 4a, and 4b to the position facing the center of the field magnet 1 coil, so that the part near the center of the coil can be can also be used to generate torque. Therefore, both plane parts including the center part of the coil become effective parts that generate torque over the entire area, and the efficiency of the motor can be greatly improved. Further, by providing the field magnet inside the coil, magnetic leakage does not occur on the case side.

As detailed above, according to the present invention, the effective area of the coil that generates torque can be increased, so the efficiency of the motor can be greatly improved, and even a motor structure with an outer diameter of 40 mm or less can achieve an efficiency of 60% or more. Since the characteristics can be obtained, it is possible to downsize the motor.

The coreless motor according to the present invention is most suitable for use in tape decks, car stereo motors, micro cassette stan motors, player direct drive motors, video disk spindle motors, PCM motors, and the like.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional example of a coreless motor, and FIG. 2 is a sectional view showing an embodiment of a coreless motor according to the present invention. Explanation of symbols of main parts 3α, 3b, 4α, 4b...Field magnet 5
... Bearing strut 8 ... Yoke 9 ... Rotor shaft 11 ... Armature coil 12 ... Commutator 13α, 13b ... Printing applicant
Pioneer Co., Ltd. 1 Patent Attorney Hikomu Itozaimoto / [] 7 Imo, 212]

Claims (3)

[Claims] (1) An armature coil that is freely rotatable and has an air-core disk shape and is wound in the radial direction passing through the vicinity of the rotation axis, and an armature coil that is stationary inside the armature coil and is provided with a rotation axis of the armature coil. at least two pairs of field magnets provided so as to have opposite polarities in directions; a first magnetic member provided outside the armature coil to form a magnetic path; and a central portion of the armature coil. 1. A coreless motor comprising: a commutator provided in the motor; and a brush slidingly in contact with the commutator. (2) The at least two pairs of field magnets 7 each have a second
2. The coreless motor according to claim 1, wherein the coreless motor is coupled via a magnetic member. (3) The coreless motor according to claim 1, wherein the first magnetic member is a case member.